/* ============================================================================
   PHONES PAGE STYLES - PROFESSIONAL VERSION (MATCHING LAPTOPS)
   Nasser Telecom - Multi-Brand Phone Showcase
   ============================================================================ */

/* ============================================================================
   CSS CUSTOM PROPERTIES (DESIGN TOKENS)
   ============================================================================ */
:root {
    /* Brand Gradients */
    --iphone: linear-gradient(135deg, #007AFF, #5856D6);
    --samsung: linear-gradient(135deg, #1428A0, #1C3FEB);
    --honor: linear-gradient(135deg, #FF6B35, #FF9500);
    --huawei: linear-gradient(135deg, #FF0000, #FF6B35);
    --xiaomi: linear-gradient(135deg, #FF6900, #FF9500);
    --oneplus: linear-gradient(135deg, #EB0028, #FF0033);
    --google: linear-gradient(135deg, #4285F4, #34A853);
    --other: linear-gradient(135deg, #8E44AD, #9B59B6);
    
    /* Primary Colors */
    --primary: #007AFF;
    --primary-dark: #0056CC;
    --secondary: #5856D6;
    --secondary-dark: #4A48C4;
    
    /* Neutral Colors */
    --text-primary: #1D1D1F;
    --text-secondary: #666666;
    --text-tertiary: #8E8E93;
    --border-light: rgba(0, 0, 0, 0.06);
    --border-medium: rgba(0, 0, 0, 0.12);
    
    /* Background Colors */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F5F5F7;
    --bg-tertiary: #E5E5EA;
    
    /* Status Colors */
    --success: #34C759;
    --warning: #FF9500;
    --info: #5AC8FA;
    --danger: #FF3B30;
    
    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);
    --shadow-primary: 0 8px 24px rgba(0, 122, 255, 0.25);
    
    /* Spacing */
    --spacing-xs: 8px;
    --spacing-sm: 12px;
    --spacing-md: 20px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
    --spacing-2xl: 64px;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-2xl: 24px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'SF Pro Text', 'Segoe UI', sans-serif;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    --font-weight-extrabold: 800;
}

/* ============================================================================
   BASE STYLES
   ============================================================================ */
.phones-page {
    font-family: var(--font-family);
    background: linear-gradient(180deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================================================
   BRAND NAVIGATION
   ============================================================================ */
.brand-navigation {
    position: relative;
    margin-top: 0px;
    z-index: 10;
    background: rgba(255, 255, 255, 0.95);
    border-bottom: 1px solid var(--border-light);
    backdrop-filter: blur(10px);
}

.brand-tabs {
    display: flex;
    gap: 12px;
    padding: 10px 0;
    overflow-x: auto;
    scrollbar-width: none;
}

.brand-tabs::-webkit-scrollbar {
    display: none;
}

.brand-tab {
    padding: 9px 16px;
    background: transparent;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-full);
    font-weight: var(--font-weight-semibold);
    font-size: 0.88rem;
    color: var(--text-secondary);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 200ms ease;
    white-space: nowrap;
}

.brand-tab i {
    font-size: 0.95rem;
}

.brand-tab:hover {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.brand-tab.active {
    background: var(--bg-primary);
    color: var(--primary);
    border-color: var(--primary);
    box-shadow: inset 0 -2px 0 var(--primary);
}

/* ============================================================================
   PAGE HEADER
   ============================================================================ */
.phones-header {
    padding: var(--spacing-2xl) 0 var(--spacing-xl);
    text-align: center;
    position: relative;
    overflow: hidden;
    animation: fadeInUp var(--transition-slow);
}

@keyframes fadeInUp {
    from {
        transform: translateY(30px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.phones-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100%;
    background: linear-gradient(135deg, rgba(0, 122, 255, 0.03) 0%, rgba(88, 86, 214, 0.03) 100%);
    z-index: -1;
}

.phones-header::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(0, 122, 255, 0.05) 0%, transparent 70%);
    animation: pulse 8s ease-in-out infinite;
    z-index: -1;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 0.5;
    }
    50% {
        transform: scale(1.1);
        opacity: 0.8;
    }
}

.phones-header h1 {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: var(--font-weight-extrabold);
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.phones-header .subtitle {
    font-size: clamp(1rem, 2vw, 1.2rem);
    color: var(--text-secondary);
    margin: var(--spacing-sm) auto;
    line-height: 1.6;
    max-width: 800px;
    font-weight: var(--font-weight-medium);
}

/* ============================================================================
   FILTERS SECTION
   ============================================================================ */
.filters-section {
    background: var(--bg-primary);
    border-radius: var(--radius-2xl);
    padding: var(--spacing-xl);
    margin: 0 var(--spacing-md) var(--spacing-2xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-light);
    transition: box-shadow var(--transition-base);
}

.filters-section:hover {
    box-shadow: var(--shadow-xl);
}

.filters-section .container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.filter-group {
    animation: fadeIn var(--transition-smooth) backwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.filter-group:nth-child(1) { animation-delay: 0ms; }
.filter-group:nth-child(2) { animation-delay: 50ms; }
.filter-group:nth-child(3) { animation-delay: 100ms; }
.filter-group:nth-child(4) { animation-delay: 150ms; }
.filter-group:nth-child(5) { animation-delay: 200ms; }
.filter-group:nth-child(6) { animation-delay: 250ms; }
.filter-group:nth-child(7) { animation-delay: 300ms; }

.filter-group h3 {
    font-size: 1.1rem;
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 12px;
}

.filter-group h3::before {
    content: '';
    width: 6px;
    height: 24px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: var(--radius-sm);
    box-shadow: 0 2px 8px rgba(0, 122, 255, 0.3);
}

.filter-options {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.filter-btn {
    padding: 11px 22px;
    background: var(--bg-secondary);
    border: 2px solid transparent;
    border-radius: 10px;
    font-weight: var(--font-weight-semibold);
    font-size: 0.9rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-base);
    white-space: nowrap;
    position: relative;
    overflow: hidden;
}

.filter-btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(0, 122, 255, 0.1);
    transform: translate(-50%, -50%);
    transition: width var(--transition-smooth), height var(--transition-smooth);
}

.filter-btn:hover::before {
    width: 300px;
    height: 300px;
}

.filter-btn:hover {
    background: var(--bg-tertiary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
    border-color: var(--border-light);
}

.filter-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--bg-primary);
    border-color: var(--primary);
    box-shadow: var(--shadow-primary);
    transform: translateY(-2px);
}

.filter-btn:active {
    transform: translateY(0);
}

/* ============================================================================
   COLOR OPTIONS
   ============================================================================ */
.color-options {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    margin-top: var(--spacing-sm);
}

.color-option {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    border: 3px solid var(--bg-secondary);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
    position: relative;
}

.color-option::before {
    content: '';
    position: absolute;
    inset: -6px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    opacity: 0;
    transition: opacity var(--transition-base);
    z-index: -1;
}

.color-option:hover {
    transform: scale(1.15);
    box-shadow: var(--shadow-md);
}

.color-option.active {
    border-color: var(--primary);
    transform: scale(1.15);
    box-shadow: var(--shadow-primary);
}

.color-option.active::before {
    opacity: 1;
}

/* ============================================================================
   SEARCH BOX
   ============================================================================ */
.search-box {
    position: relative;
    margin-top: var(--spacing-sm);
}

.search-input {
    width: 100%;
    padding: 16px 24px;
    padding-right: 64px;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: var(--font-family);
    transition: all var(--transition-base);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-weight: var(--font-weight-medium);
}

.search-input::placeholder {
    color: var(--text-tertiary);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--bg-primary);
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.08);
}

.search-btn {
    position: absolute;
    right: 8px;
    top: 50%;
    transform: translateY(-50%);
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border: none;
    border-radius: 10px;
    color: var(--bg-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
    font-size: 1.1rem;
}

.search-btn:hover {
    transform: translateY(-50%) scale(1.05);
    box-shadow: var(--shadow-primary);
}

.search-btn:active {
    transform: translateY(-50%) scale(0.95);
}

/* ============================================================================
   BRAND INDICATOR
   ============================================================================ */
.current-brand-indicator {
    background: var(--bg-primary);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-md);
    border-left: 6px solid var(--primary);
    transition: all var(--transition-base);
    animation: slideInLeft var(--transition-smooth);
}

@keyframes slideInLeft {
    from {
        transform: translateX(-30px);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.current-brand-indicator:hover {
    box-shadow: var(--shadow-lg);
    transform: translateX(5px);
}

.brand-name {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: var(--font-weight-extrabold);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.brand-name::before {
    content: '';
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    background: var(--iphone);
    display: inline-block;
    box-shadow: var(--shadow-md);
}

.phone-count {
    font-size: 1rem;
    font-weight: var(--font-weight-semibold);
    color: var(--text-secondary);
    background: var(--bg-secondary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.current-brand-indicator:hover .phone-count {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--bg-primary);
    box-shadow: var(--shadow-primary);
}

/* ============================================================================
   PRODUCT GRID
   ============================================================================ */
.models-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-2xl);
}

.product-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-smooth);
    position: relative;
    border: 1px solid var(--border-light);
    height: 100%;
    display: flex;
    flex-direction: column;
    animation: cardAppear var(--transition-smooth) backwards;
}

@keyframes cardAppear {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.product-card:nth-child(1) { animation-delay: 0ms; }
.product-card:nth-child(2) { animation-delay: 50ms; }
.product-card:nth-child(3) { animation-delay: 100ms; }
.product-card:nth-child(4) { animation-delay: 150ms; }
.product-card:nth-child(5) { animation-delay: 200ms; }
.product-card:nth-child(6) { animation-delay: 250ms; }

.product-card:hover {
    transform: translateY(-12px) scale(1.02);
    box-shadow: var(--shadow-xl);
    border-color: rgba(0, 122, 255, 0.2);
}

.product-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.product-card:hover::before {
    transform: scaleX(1);
}

/* ============================================================================
   BADGES
   ============================================================================ */
.brand-badge {
    position: absolute;
    top: var(--spacing-md);
    left: var(--spacing-md);
    padding: 8px 18px;
    border-radius: var(--radius-full);
    font-size: 11px;
    font-weight: var(--font-weight-bold);
    color: var(--bg-primary);
    text-transform: uppercase;
    letter-spacing: 0.8px;
    z-index: 2;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
}

.brand-badge-iphone { background: var(--iphone); }
.brand-badge-samsung { background: var(--samsung); }
.brand-badge-honor { background: var(--honor); }
.brand-badge-huawei { background: var(--huawei); }
.brand-badge-xiaomi { background: var(--xiaomi); }
.brand-badge-oneplus { background: var(--oneplus); }
.brand-badge-google { background: var(--google); }
.brand-badge-other { background: var(--other); }

.badge {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    padding: 6px 16px;
    border-radius: var(--radius-full);
    font-size: 10px;
    font-weight: var(--font-weight-bold);
    color: var(--bg-primary);
    text-transform: uppercase;
    letter-spacing: 0.8px;
    z-index: 2;
    box-shadow: var(--shadow-md);
    backdrop-filter: blur(10px);
}

.badge-new {
    background: linear-gradient(135deg, var(--success), #2AB44A);
}

.badge-used {
    background: linear-gradient(135deg, var(--warning), #FF7B00);
}

.badge-refurbished {
    background: linear-gradient(135deg, var(--info), #4AB5E8);
}

/* ============================================================================
   PRODUCT IMAGE
   ============================================================================ */
.product-image {
    height: 220px;
    background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-lg);
    position: relative;
    overflow: hidden;
}

.product-image::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100%;
    background: radial-gradient(circle at 50% 50%, rgba(0, 122, 255, 0.03), transparent);
    pointer-events: none;
}

.product-image img {
    max-width: 85%;
    max-height: 85%;
    object-fit: contain;
    transition: transform var(--transition-slow);
    position: relative;
    z-index: 1;
    filter: drop-shadow(0 4px 12px rgba(0, 0, 0, 0.1));
}

.product-card:hover .product-image img {
    transform: scale(1.08) rotate(-2deg);
}

/* ============================================================================
   PRODUCT INFO
   ============================================================================ */
.product-info {
    padding: var(--spacing-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.product-title h3 {
    font-size: 1.4rem;
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
    line-height: 1.3;
    letter-spacing: -0.01em;
}

.product-specs {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: var(--font-weight-medium);
}

.product-specs i {
    color: var(--primary);
    font-size: 0.9rem;
}

/* ============================================================================
   PRICING
   ============================================================================ */
.price-section {
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--bg-secondary);
}

.product-price {
    font-size: 2.2rem;
    font-weight: var(--font-weight-extrabold);
    color: var(--text-primary);
    display: flex;
    align-items: baseline;
    letter-spacing: -0.02em;
}

.currency {
    font-size: 1.3rem;
    margin-right: 4px;
    color: var(--primary);
    font-weight: var(--font-weight-bold);
}

.old-price {
    font-size: 1rem;
    color: var(--text-tertiary);
    text-decoration: line-through;
    margin-left: var(--spacing-sm);
    font-weight: var(--font-weight-medium);
}

/* ============================================================================
   PRODUCT DETAILS
   ============================================================================ */
.product-details {
    margin-bottom: var(--spacing-lg);
    flex: 1;
}

.detail-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid var(--bg-secondary);
    transition: all var(--transition-fast);
}

.detail-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.detail-item:hover {
    padding-left: var(--spacing-xs);
    background: var(--bg-secondary);
    margin-left: calc(var(--spacing-xs) * -1);
    padding-left: var(--spacing-sm);
    padding-right: var(--spacing-xs);
    margin-right: calc(var(--spacing-xs) * -1);
    border-radius: var(--radius-sm);
}

.detail-label {
    font-size: 0.9rem;
    color: var(--text-tertiary);
    font-weight: var(--font-weight-medium);
}

.detail-value {
    font-size: 0.95rem;
    font-weight: var(--font-weight-semibold);
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.detail-value i {
    color: var(--primary);
    font-size: 0.85rem;
}

/* ============================================================================
   BATTERY HEALTH & CYCLE COUNT STYLES
   ============================================================================ */
.battery-health-item,
.cycle-count-item {
    background: rgba(0, 0, 0, 0.02);
    border-radius: var(--radius-sm);
    padding: 10px;
    margin: var(--spacing-sm) 0;
}

.battery-health-item {
    border-left: 3px solid #27ae60;
}

.cycle-count-item {
    border-left: 3px solid #3498db;
}

.battery-indicator,
.cycle-indicator {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.battery-bar-container {
    flex: 1;
    min-width: 100px;
    height: 10px;
    background: rgba(0, 0, 0, 0.08);
    border-radius: 5px;
    overflow: hidden;
    position: relative;
}

.battery-bar {
    height: 100%;
    border-radius: 5px;
    transition: width 0.8s cubic-bezier(0.34, 1.56, 0.64, 1);
    position: relative;
    animation: batteryFill 1.2s ease-out;
}

.battery-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(90deg, 
        rgba(255,255,255,0.3) 0%, 
        rgba(255,255,255,0.1) 50%, 
        rgba(0,0,0,0.1) 100%);
    border-radius: 5px;
}

@keyframes batteryFill {
    0% {
        width: 0%;
        opacity: 0.7;
    }
    100% {
        width: var(--battery-width, 100%);
        opacity: 1;
    }
}

.battery-percentage,
.cycle-count {
    font-weight: var(--font-weight-extrabold);
    font-size: 1rem;
    min-width: 45px;
    text-align: center;
    padding: 4px 8px;
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.9);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.battery-label,
.cycle-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    min-width: 120px;
    text-align: right;
    font-weight: var(--font-weight-semibold);
}

/* Color variations for battery health */
.battery-percentage[data-health="excellent"],
.cycle-count[data-cycles="new"] {
    color: #27ae60;
    background: rgba(39, 174, 96, 0.1);
}

.battery-percentage[data-health="good"],
.cycle-count[data-cycles="low"] {
    color: #f39c12;
    background: rgba(243, 156, 18, 0.1);
}

.battery-percentage[data-health="fair"],
.cycle-count[data-cycles="medium"] {
    color: #e67e22;
    background: rgba(230, 126, 34, 0.1);
}

.battery-percentage[data-health="poor"],
.cycle-count[data-cycles="high"] {
    color: #e74c3c;
    background: rgba(231, 76, 60, 0.1);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

/* ============================================================================
   PRODUCT ACTIONS
   ============================================================================ */
.product-actions {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: auto;
}

.product-actions .btn {
    flex: 1;
    padding: 15px;
    font-weight: var(--font-weight-semibold);
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    transition: all var(--transition-base);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    border: none;
    position: relative;
    overflow: hidden;
}

.product-actions .btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width var(--transition-smooth), height var(--transition-smooth);
}

.product-actions .btn:active::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: var(--bg-primary);
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--secondary-dark));
    transform: translateY(-3px);
    box-shadow: var(--shadow-primary);
}

.btn-primary:active {
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--bg-primary);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.btn-outline:active {
    transform: translateY(-1px);
}

/* ============================================================================
   EMPTY STATE & NO RESULTS
   ============================================================================ */
.empty-state, 
.no-results {
    text-align: center;
    padding: var(--spacing-2xl) var(--spacing-md);
    grid-column: 1 / -1;
    animation: fadeInUp var(--transition-smooth);
}

.empty-state-content i, 
.no-results i {
    font-size: 5rem;
    color: var(--text-tertiary);
    margin-bottom: var(--spacing-lg);
    opacity: 0.3;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-20px);
    }
}

.empty-state h3, 
.no-results h3 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    font-weight: var(--font-weight-bold);
}

.empty-state p, 
.no-results p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

.empty-state-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-top: var(--spacing-lg);
    flex-wrap: wrap;
}

/* ============================================================================
   COLOR LEGEND
   ============================================================================ */
.color-legend {
    background: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-top: var(--spacing-xl);
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    justify-content: center;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
}

.color-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-base);
    padding: var(--spacing-xs);
    border-radius: var(--radius-sm);
}

.color-item:hover {
    background: var(--bg-secondary);
    transform: scale(1.05);
}

.color-dot {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    border: 3px solid var(--bg-secondary);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.color-item:hover .color-dot {
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

.color-name {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: var(--font-weight-medium);
}

/* ============================================================================
   BRAND-SPECIFIC HEADER COLORS
   ============================================================================ */
.page-header-iphone .phones-header::before { background: linear-gradient(135deg, rgba(0, 122, 255, 0.03), rgba(88, 86, 214, 0.03)); }
.page-header-samsung .phones-header::before { background: linear-gradient(135deg, rgba(20, 40, 160, 0.03), rgba(28, 63, 235, 0.03)); }
.page-header-honor .phones-header::before { background: linear-gradient(135deg, rgba(255, 107, 53, 0.03), rgba(255, 149, 0, 0.03)); }
.page-header-huawei .phones-header::before { background: linear-gradient(135deg, rgba(255, 0, 0, 0.03), rgba(255, 107, 53, 0.03)); }
.page-header-xiaomi .phones-header::before { background: linear-gradient(135deg, rgba(255, 105, 0, 0.03), rgba(255, 149, 0, 0.03)); }
.page-header-oneplus .phones-header::before { background: linear-gradient(135deg, rgba(235, 0, 40, 0.03), rgba(255, 0, 51, 0.03)); }
.page-header-google .phones-header::before { background: linear-gradient(135deg, rgba(66, 133, 244, 0.03), rgba(52, 168, 83, 0.03)); }
.page-header-other .phones-header::before { background: linear-gradient(135deg, rgba(142, 68, 173, 0.03), rgba(155, 105, 189, 0.03)); }

/* ============================================================================
   RESPONSIVE DESIGN
   ============================================================================ */
@media (max-width: 1200px) {
    .filters-section .container {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-lg);
    }
    
    .models-grid {
        grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    }
}

@media (max-width: 768px) {
    .phones-header {
        padding: var(--spacing-sm) 0 var(--spacing-lg);
    }
    
    .brand-navigation {
        margin-bottom: 0;
    }
    
    .brand-tabs {
        padding: var(--spacing-sm) var(--spacing-md);
    }
    
    .brand-tab {
        padding: 12px 20px;
        font-size: 0.9rem;
    }
    
    .filters-section {
        padding: var(--spacing-lg);
        margin: 0 var(--spacing-md) var(--spacing-xl);
        border-radius: var(--radius-lg);
    }
    
    .filters-section .container {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .models-grid {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: var(--spacing-md);
    }
    
    .current-brand-indicator {
        padding: var(--spacing-md) var(--spacing-md);
        flex-direction: column;
        gap: var(--spacing-sm);
        text-align: center;
    }
    
    .brand-name {
        font-size: 1.5rem;
        flex-direction: column;
    }
    
    .battery-indicator,
    .cycle-indicator {
        flex-direction: column;
        align-items: stretch;
        gap: 6px;
    }
    
    .battery-bar-container {
        min-width: 100%;
    }
    
    .battery-label,
    .cycle-label {
        text-align: left;
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .models-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }
    
    .product-actions {
        flex-direction: column;
    }
    
    .empty-state-actions {
        flex-direction: column;
        align-items: stretch;
    }
    
    .empty-state-actions .btn {
        width: 100%;
    }
    
    .brand-tabs {
        gap: var(--spacing-xs);
    }
    
    .brand-tab {
        padding: 10px 18px;
        font-size: 0.85rem;
    }
    
    .filters-section {
        padding: var(--spacing-md);
        margin: 0 var(--spacing-sm) var(--spacing-lg);
    }
    
    .product-price {
        font-size: 1.8rem;
    }
    
    .color-legend {
        padding: var(--spacing-md);
        gap: var(--spacing-md);
    }
}

/* ============================================================================
   UTILITIES
   ============================================================================ */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

html {
    scroll-behavior: smooth;
}

*:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

::selection {
    background: var(--primary);
    color: var(--bg-primary);
}

.brand-tab,
.filter-btn,
.btn,
.color-option {
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
}

/* ============================================================================
   LOADING STATES
   ============================================================================ */
@keyframes shimmer {
    0% {
        background-position: -1000px 0;
    }
    100% {
        background-position: 1000px 0;
    }
}

.loading-skeleton {
    background: linear-gradient(90deg, var(--bg-secondary) 25%, var(--bg-tertiary) 50%, var(--bg-secondary) 75%);
    background-size: 2000px 100%;
    animation: shimmer 2s infinite;
}

/* ============================================================================
   PRINT STYLES
   ============================================================================ */
@media print {
    .brand-navigation,
    .filters-section,
    .product-actions {
        display: none;
    }
    
    .product-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid var(--border-medium);
    }
}